Unless this Mummy reboot really takes off, the Mission: Impossible movies are basically Tom Cruise’s last real connection to the mainstream Hollywood success that he used to effortlessly command just a few years ago. Even with his high-profile divorce, his occasionally strange behavior, and the fact that his entire life has become an advertisement for the magical powers of Scientology, the Mission: Impossible series has ensured that he’s still a big-time movie star. That’s why it’s important for him to keep making those movies successful, because without them, he’ll just be another wealthy acolyte waiting until God returns from space to free mankind from this lizard monster prison universe or whatever.

Part of making the Mission: Impossible movies popular involves each one being bigger and better than the last one, especially in terms of the ridiculous stunts that Cruise has to do. Mission: Impossible—Ghost Protocol involved him climbing the Burj Khalifa in Dubai, Mission: Impossible—Rogue Nationhad him cling to an airplane as it took off, and it sounds like Mission: Impossible 6 is going to have a stunt so insane that Cruise has been training to do it for over a year. That’s according to Collider, which spoke with M:I 6 producer David Ellison about the film.

According to Ellison, this new stunt is going to be “the most impressive and unbelievable thing that Tom Cruise has done in a movie,” and he’s been preparing for it since “right after Rogue Nation came out.” He wouldn’t offer any specifics, but he explained that Cruise prefers doing real stunts like this because “the audience can tell when it’s you on a green screen or when you’re actually doing it live.”

The subtext there is that it’s important that the audience specifically sees Tom Cruise doing these stunts, because that makes him—and the anticipation of seeing his next big stunt—an indelible part of the Mission: Impossible series’ appeal. That means that as long as Cruise and this series continues to do well, it will be tough for the studio to step in and replace him with someone younger/not deeply involved with Scientology.